1. Field of the Invention
The present invention relates to a lock device, and more particularly to a lock device including an improved structure for preventing the lock device from being destroyed or damaged by the unauthorized persons and for allowing the lock device to be used or operated even when the lock device has been destroyed or damaged by the unauthorized persons.
2. Description of the Prior Art
Typical lock devices are normally attached to a door panel, and comprise a dead bolt extendible out of the lock casing for engaging with a door frame and for selectively locking the door panel to the door frame.
For example, U.S. Pat. No. 4,820,330 to Lin, U.S. Pat. No. 5,010,752 to Lin, and U.S. Pat. No. 5,074,607 to Lin disclose three of the typical lock devices each also comprising a lock casing secured to a door panel, and a dead bolt extendible out of the lock casing for engaging with a door frame, and a handle attached or coupled to the dead bolt of the lock device for rotating or operating the handle.
Normally, a spring biasing member is attached to the handle or coupled between the handle and the lock casing for biasing or recovering the handle back to the original position and also for biasing or recovering the dead bolt to engage with the door frame after the handle is released by the user.
However, when the spring biasing member is destroyed or damaged by the unauthorized persons, the dead bolt may no longer be biased or forced by the spring biasing member to engage with the door frame after the handle is released by the user, and the door panel may no longer be locked or anchored to the door frame with the dead bolt.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional lock devices for door panels.